The present invention relates to the preparation of a beverage and in particular a beverage that comprises a cocoa based material having an enhanced level of polyphenols.
It is known that fresh cocoa beans contains approximately 40% water, 30 to 35% lipids, 4 to 6% polyphenols or polyphenol derivatives, 1.5% xanthines, with the rest being mainly constituted by proteins, starch, cellulose and sugars. Further information on the composition of cocoa beans may be found in the following articles:
Cocoa procyandins: major flavanoids and identification of some minor metabolites by L. J. Porter, Z. Ma and B. G. Chan, published in Phytochemistry vol. 35, No. 5 p 1657-1663, 1991 and
Epicatechin content in fermented and unfermented cocoa beans by H. Kim and P. G. Keeney, published in Journal of Food Science-vol. 49 (1984) p 1090-1092.
Cocoa is grown in South America, Africa and elsewhere. When harvested, its fruits or pods are picked, and the beans undergo a pre-treatment which consists of fermenting for five to six days before being dried. During this fermentation, a certain number of biochemical reactions occur, which involve, in particular, the destruction of pathogenic micro-organisms, the formation of aroma precursors and a partial degradation of polyphenols following enzymatic oxidation or tanning of proteins. It is considered that 70 to 80% of polyphenols are degraded during traditional fermentation.
Polyphenols are a diverse group of compounds (Ferriera et al., “Diversity of Structure and Function in Oligomeric Flavanoids, Tetrahedron, 48:10, 1743-1803, 1992). They occur widely in a variety of plants, some of which enter into the food chain. Several thousands of molecules with a polyphenol structure have been identified in higher plants, and several hundreds are found in edible plants. These molecules are secondary metabolites of plants and generally involved in defense against external stressors, like ultraviolet radiation or aggression by pathogens (Manach, C., et al., Polyphenols: food sources and bioavailability. Am J Clin Nutr, 2004. 79: p. 727-47).
Polyphenols may be further classified into different groups as a function of the number of aromatic rings and the structural elements that bind these rings together. Distinctions are made between flavonoids, non-flavonoids and phenolic acids (see FIG. 1), with the flavanoids being the largest group with more than 2000 known compounds. FIG. 1 shows the classification hierarchy of polyphenols with epicatechin, catechin and the procyanidins being the predominant class of polyphenols in cocoa.
Cocoa and cocoa-derived products are rich in polyphenols and particularly in flavonoids, a class of compounds that occur in a wide variety of fruits, vegetables, teas and red wines. It is well documented that cocoa and cocoa products, like chocolate, are among the richest sources of polyphenols (Ding, E., et al., Chocolate and prevention of cardiovascular disease: a systemic review. Nutr & Met, 2006, 3:1-12).
In addition, cocoa has been described as being rich in a particular subgroup of flavonoids named flavanols (flavan-3-ols). The flavanols are present as the monomers epicatechin and catechin or as oligomers of epicatechin and/or catechin called procyanidins. The chemical structures of the different flavanols found in cocoa are shown in FIGS. 2 and 3.
FIG. 2 shows the chemical structure of the flavanol monomers in cocoa. FIG. 3 shows the chemical structure of flavanol dimers and oligomers in cocoa.
An increasing body of evidence supports the concept that dietary intake of polyphenols promotes health and attenuates or delays the onset of various diseases, including cardiovascular diseases, cancer, and other chronic diseases.
Flavanols in cocoa and cocoa products exert some beneficial vascular effects (Schroeter, H., et al., Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans. PNAS, 2006. 103: p. 1024-1029; Engler, M. B., et al., Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults. Journal of the American College of Nutrition, 2004. 23(3): p. 197-204).
Flavanols in cocoa and cocoa products reduce the risk for cardiovascular morbidity and mortality (Buijsse, B., et al., Cocoa intake, blood pressure and cardiovasular mortality. The Zutphen Elderly Study. Arch Intern Med, 2006. 166: p. 411-417). Flavanols in cocoa and cocoa products also reduce the risk for cancer (Yamagishi, M., et al., Chemoprevention of lung carcinogenesis by cacao liquor proanthocyanidins in a male rat multi-organ carcinogenesis model. Cancer letters, 2003. 191: p. 49-57). Flavanols in cocoa and cocoa products may contribute to the prevention of neurodegenerative diseases and diabetes mellitus (Bayard, V., et al., Does flavanol intake influence mortality from nitric oxide-dependent processes? Ischemic heart disease, stroke, diabetes mellitus, and cancer in Panama. Int. J. Med. Sci., 2007. 4(1): p. 53-58).
A research group found that long-term ingestion of cocoa flavanols contributes to photoprotection against UV-irradiation, increases dermal blood flow and skin thickness, improves skin density and moisture, and influences significantly the skin structure and roughness (Heinrich, U., et al., Long-term ingestion of high flavanol cocoa provides photoprorection against UV-induced erythema and improves skin condition in women. J. Nutr., 2006. 136: p. 1565-1569). In another study from the same group, an increase in dermal blood flow and oxygen saturation of haemoglobin was detected within two hours after ingestion of a single-dose of flavanol-rich cocoa (Neukam, K., et al., Consumption of flavanol-rich cocoa acutely increases microcirculation in human skin. Eur J Nutr, 2007. 46: p. 53-56).
Polyphenols are powerful natural anti-oxidant and anti-radical substances. Polyphenol extracts and preparations which contain them are usually used in the following indications: circulatory disorders, venous-lymphatic insufficiency, cutaneous capillary fragility, retinal circulatory disorders, haemorrhoids, rashes caused by the sun or associated with the effect of radiation (prevention of damage caused by radiotherapy), hypertension, hypercholesterolemia, various viral and microbial illnesses. Numerous publications have revealed types of action at a molecular level by which they are capable of fighting major illnesses including:
Cardiovascular Diseases:
Platelet antiaggregates (Petroni, A., M. Blasevich, M. Salami, N. Papini, G. F. Montedoro and C. Galli, “Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil”. Thromb Res, 1995. 78(2): p. 151-160)
Anti-inflammatories and protection against the oxidation of LDL-cholesterols (Frankel, E., J. Kanner, J. German, E. Parks and J. Kinsella, “Inhibition of oxidation of human low-density lipoprotein by phenolic substances in red wine”. Lancet, 1993. 341(8843): p. 454-457).
Protection against the oxidation of eicosanoids (Pace-Asciak, C. R., S. Hahn, E. P. Diamandis, G. Soleas and D. M. Goldberg, “The red wine phenolics transresveratrol and quercetin block human platelet aggregation and eicosanoid synthesis: implications for protection against coronary heart disease”. Clin Chim Acta, 1995. 235(2): p. 207-219)
Anti-atheroscierotics (Yamakoshi, J., S. Kataoka, T. Koga and T. Ariga, “Proanthocyanidin-rich extract from grape seeds attenuates the development of aortic atherosclerosis in cholesterol-fed rabbits”. Atherosclerosis, 1999. 142(1): p. 139-149)
Anti-thrombotics (Fuhrman, B., A. Lavy and M. Aviram, “Consumption of red wine with meals reduces the susceptibility of human plasma and low-density lipoprotein to lipid peroxidation”. Am J Clin Nutr, 1995. 61(3): p. 549-554)
Alzheimers (Orgogozo, J. M., J. F. Dartigues, S. Lafont, L. Letenneur, D. Commenges, R. Salamon, S. Renaud and M. Breteler, “Wine consumption and dementia in the elderly: A prospective community study in the Bordeaux area”. Rev Neurol, 1997. 153(3): p. 185-192)
Cancer (Jang, M. S., E. N. Cai, G. O. Udeani, K. V. Slowing, C. F. Thomas, C. W. W. Beecher, H. H. S. Fong, N. R. Farnsworth, A. D. Kinghorn, R. G. Mehta, R. C. Moon and J. M. Pezzuto, “Cancer chemopreventive activity of resveratrol, a natural product derived from grapes”. Science, 1997. 275(5297): p. 218-220)
Taking into account the fact that cocoa contains polyphenols and of the importance of the use of polyphenols in the medical field, this has led to an attempt to extract the polyphenol compounds from cocoa, with the aim of creating dietetic food and drinks containing these antioxidants. The traditional pre-treatment, comprising fermentation followed by a drying operation, constitutes a major drawback in the sense that it reduces the levels of polyphenols contained in the resulting cocoa products.
US 2004/096566 discloses a process for carrying out the extraction under specific conditions that makes it possible to process cocoa beans to provide products with a high polyphenol content and enriched, (in comparison to the initial content of the beans) with certain useful lipid derivatives. The process disclosed in US 2004/096566 comprises the use of fresh beans, not having undergone a pre-treatment or defatting, these beans having had their pulp and shell removed, in such a way as to obtain clean kernels, the grinding of said kernels in the presence of a solvent, the maceration of the ground kernels under conditions allowing the desired compounds to be extracted, the filtration of the maceration mixture, and the recovery of the extract containing said compounds from the filtrate.
US 2007/0258920 discloses a further process for the production of cocoa based materials having enhanced levels of polyphenols.
WO2007/002883 discloses products, including beverages, that contain polyphenols and sterol and/or stanol esters, that are produced by a method which conserves the levels of polyphenols found in the starting materials. This documents teaches that the acidification of polyphenol-containing ingredients helps to retain their levels of polyphenols during their incorporation into the final products. The disclosed method is based on combining all the ingredients of the product together and thereafter adding acid to reduce the pH before further processing.
However, problems relating to handling, stability and consumer appeal can occur with cocoa based beverages. These problems are particularly relevant in the case of beverages that contain cocoa based materials having an enhanced level of polyphenols. The present invention seeks to provide an improved process for preparing a beverage containing a cocoa based material having an enhanced level of polyphenols, and an improved beverage that contains a cocoa based material having an enhanced level of polyphenols.
According to the present invention there is provided a process for producing a beverage comprising a cocoa material having an enhanced level of polyphenols, the process comprising the steps of:                (a) adding a base to an aqueous phase to adjust the pH to between about 6.5 and about 7.5,        (b) mixing ingredients into the aqueous phase to give a dispersion, the ingredients including the cocoa material having an enhanced level of polyphenols,        (c) performing a thermal treatment on the dispersion, comprising heating the dispersion to over about 85° C. for at least about 5 seconds, and        (d) cooling the treated dispersion.        
Preferably, the aqueous phase is milk.
Conveniently, the milk is a low fat milk.
Advantageously, the aqueous phase is water.
Preferably, the base comprises potassium hydroxide, sodium hydroxide and/or potassium carbonate.
Conveniently, the pH of the aqueous phase in step (a) is adjusted to between about 6.7 and about 7.2.
Advantageously, the pH of the aqueous phase in step (a) is adjusted to between about 6.85 and about 7.1.
Preferably, the pH of the aqueous phase in step (a) is adjusted to between about 6.9 and about 7.0.
Conveniently, the cocoa material having an enhanced level of polyphenols is a cocoa powder.
Advantageously, the cocoa powder contains a higher level of polyphenols than alkalized cocoa powder.
Preferably, the cocoa powder has an ORAC value of greater than 1000 micromoles TE/g.
Conveniently, the cocoa powder has an ORAC value of greater than 1500 micromoles TE/g.
Advantageously, the cocoa powder contains at least 50 mg/g of polyphenols.
Preferably, the cocoa powder contains at least 80 mg/g of polyphenols.
Conveniently, the cocoa powder contains at least 100 mg/g of polyphenols.
Advantageously, the ingredients are selected from the group consisting of cocoa powder, polyphenol-enhanced cocoa powder, thickening agents, flavouring agents, sugar, sugar replacers, and mixtures thereof.
Preferably, the thermal treatment comprises heating the dispersion to above about 90° C.
Conveniently, the thermal treatment comprises heating the dispersion to between about 93° C. and 97° C.
Advantageously, the thermal treatment comprises heating the dispersion for at least 10 seconds.
Preferably, the thermal treatment comprises heating the dispersion for at least 20 seconds.
Conveniently, the thermal treatment comprises heating the dispersion for between about 25 and 50 seconds.
Advantageously, the thermal treatment is performed using a tubular heat exchanger and/or a plate heat exchanger.
Preferably, a UHT treatment is performed on the dispersion after the thermal treatment.
Conveniently, the process further comprises homogenizing the dispersion after step (b).
Advantageously, the homogenization is performed in two steps.
Preferably, the dispersion is cooled to a temperature of less than about 30° C. in step (d).
Conveniently, the dispersion is cooled to a temperature of between about 15 and about 25° C. in step (d).
Advantageously, the process further comprises packaging the beverage into a container.
According to another aspect of the invention, there is provided a beverage comprising:                0.5 to 3% cocoa powder,        0.5 to 3% polyphenol-enhanced cocoa powder,        0.01 to 0.07% carrageenan,        5 to 20% sugar, and        milk to 100%,wherein the beverage is substantially free of agglomerated protein.        
According to a further aspect of the invention, there is provided the use of a beverage of the invention for the prevention or treatment of cardiovascular disease, poor cognitive performance, poor skin health, poor immune system performance, cancer, prostrate enlargement, obesity, and/or depression.